Data from: Exfoliated transition metal dichalcogenide nanosheets for supercapacitor and sodium ion battery applications

Growing concerns regarding the safety, flammability, and hazards posed by
Li-ion systems have led to research on alternative rechargeable metal-ion
electrochemical storage technologies. Among the most notable of these are
Na-ion supercapacitors and batteries, motivated in part because of the
similar size and electrochemistry of Li and Na ions. However, sodium ion
batteries (SIBs) come with their own set of issues, especially the large
size of the Na+ ion, its relatively sluggish kinetics and low energy
densities. This makes the development of novel materials and appropriate
electrode architecture is of absolute significance. Transition metal
dichalcogenides (TMDs), in this regard have attracted a lot of attention
due of their relative ease of exfoliation, diverse morphologies and
architectures with superior electronic properties. Here, we study the
electrochemical performance of Mo based two dimensional (2D) layered TMDs
(e.g. MoS2, MoSe2, and MoTe2), exfoliated in a superacid, for battery and
supercapacitor applications. The exfoliated TMD flakes were interfaced
with reduced graphene oxide (rGO) to be used as composite electrodes.
Electron microscopy, elemental mapping, Raman spectra were used to analyze
the exfoliated material and confirm the formation of 2D TMD/rGO layer
morphology. For supercapacitor applications in aqueous media, the
sulfide-based TMD (MoS2) exhibited the best performance, providing an
areal capacitance of 60.25 mF cm-2. For SIB applications, TMD electrodes
exhibited significantly high charge capacities than the neat rGO
electrode. The initial desodiation capacities for the composite electrodes
468.84 mAh g-1 (1687.82 C g-1), 399.10 mAh g-1 (1436.76 C g-1) and 387.36
mAh g-1 (1394.49 C g-1) for MoS2, MoSe2, and MoTe2 respectively. Also, all
the composite TMD electrodes provided a coulombic efficiency of ∼100 %
after few cycles.